Removal of ammonium from aqueous solutions using zeolite synthesized from fly ash by a fusion method

► Fly ash was turned into high-crystalline zeolite by fusion method. ► The synthesized zeolite had strong ability to uptake ammonium. ► It is a easily-available and high-efficient ion exchanger for ammonium. ► Thus, it can be used to remove ammonium from municipal and industrial wastewater.